Unlocking the Potential of Adsorption in Distillery Wastewater Treatment: a Comprehensive Review

The world's top two producers of sugarcane are India and Brazil. After China, India is the second-largest manufacturer of alcoholic beverages. The distillery industry in India produces a huge amount of wastewater that is often released untreated into water bodies. Different distilleries have common pollutants that are being discharged into water bodies including wastewater, chemicals and solvents, cooling water, and agricultural runoff. Water pollution due to distilleries is causing a significant impact on the water's quality, making it unsafe for human consumption, aquatic life, and other uses and damaging the soil due to inadequately treated and indiscriminately disposed effluents. Heavy metals and organic contaminants have a major influence on the contamination of water bodies. The various adsorbents and their efficiency in distillery wastewater treatment are examined in this comprehensive review. The adsorbents like sugarcane bagasse, zeolites, chitosan, activated carbon, fly ash, and clay minerals are studied for the effective and economical treatment of distillery wastewater by researchers and are reviewed in this paper. The review of the relevant literature shows that the maximum removal efficiencies of organic matter and heavy metals vary between 44 and 99.8% with optimal pH from 2 to 7 and contact time varying from 1 to 24 h. A bibliometric study is also mentioned in this paper to justify the need for the study of distillery wastewater using adsorbents. Sustainable and economic criteria are studied through the life cycle assessment of different adsorbents for the treatment of wastewater. Overall, 78 research papers are reviewed in this paper. It has been shown that naturally occurring adsorbents and adsorbents made from agricultural waste may effectively treat distillery effluent in place of commercial activated carbons. However, it has been determined that there are still some open questions about the optimization and commercialization of suitable adsorbents, as well as the application, regeneration, reuse, and safe disposal of loaded adsorbents. Finally, the potential directions of the contamination biosorption study are presented.